DE892809C - Process for the production of azo dyes - Google Patents

Description

Process for the preparation of azo dyes It has been found that valuable azo dyes are obtained when using monooxyazo dyes that contain at least contain an unsubstituted sulfonamide group (-S 02N H2), with such aliphatic or aromatic acylating agents that are not water-solubilizing Carry groups, and if desired on the acylated dyes obtained in Substance or metal-releasing agent can act on the fiber.

While the starting dyes, which only contain non-acylated sulfonamide groups, are mostly sparingly or insoluble in water and alkalis and can therefore only be used to a limited extent for dyeing textiles, their N-acyl derivatives in the form of their ammonium or alkali salts are easily soluble in water so that wool or other fibers of a wool-like character from a neutral or weakly acidic bath can be dyed at temperatures below 1000. The dyes are also readily soluble in nitrocellulose lacquers.

With heavy metal salts they generally form poorly soluble salts, so that they can also be used for the production of lacquer dyes.

If the acylated sulfonamide group is in the zero position to the azo group, for example, by treating with metal donating agents, dyes, the metals, are obtained complex bound included. Such dyes are suitable for dyeing. Wool, Cotton, regenerated cellulose fibers, acetate rayon, paper, leather or of paints. You can also dye the dyes on the fiber first and then the Then dyeings with metal donating Treat and maintain funds then very real colorations. Also preserved on fibers pretreated with metal salts one stains of very good authenticity.

The parts mentioned in the following examples are parts by weight.

Example i A mixture of 60 parts of the monoazo dye from diazotized i-aminobenzene-4-sulfonamide and 2-oxynaphthalene and 400 parts acetic anhydride after adding small amounts of concentrated sulfuric acid for one hour Boiling heated. After working up, 35 parts of the acetylated monoazo dye are obtained, which dyes wool from a weakly acidic bath in orange-red tones. He is also suitable especially good for the production of colored lacquers.

From the monoazo dye from diazotized i-amino-6-methyl-benzene-3-sulfonamide and 2-oxynaphthalene is also obtained by heating with acetic anhydride an orange-red monoazo dye. This delivers a bright red with barium salts Barium lacquer.

Example 2 A mixture of 10 parts of the monoazo dye from diazotized i-aminobenzene-4-sulfonamide and 2-oxynaphthalene and 50 parts propionic anhydride after adding small amounts of concentrated sulfuric acid for one hour Boiling heated. The propionyl sulfonamide dye obtained dyes wool from weakly acidic Bathroom in orange-red tones.

Example 3 A mixture of 10 parts of the monoazo dye from diazotized i-aminobenzene-4-sulfonamide and i-phenyl-3-methyl-pyrazolone- (5) and 50 parts acetic anhydride after adding small amounts of concentrated sulfuric acid for one hour Boiling heated. The acylated monoazo dye obtained after the usual work-up dyes wool from a weakly acidic bath in yellow tones. Occurs also to manufacture of colored lacquers. For example, its barium compound is insoluble in water Pigment.

If the acylation is carried out with propionic anhydride instead of acetic anhydride carried out, a yellow dye with the same properties is also obtained.

A dye which turns wool yellow is also obtained by treatment the monoazo dyes from diazotized i-ami.nobenzene-3-sulfonami.d or diazotized i-amino-6-methylbenzo1-3-sulfonamide and i-phenyl-3-methyl-pyrazolone, (5) with acetic anhydride.

Example 4 A mixture of 10 parts of the monoazo dye. From diazotized i-Amino-4-chlorobenzene and 2-oxynaphthalene-6-sulfonami.d, 6o parts of acetic anhydride and small amounts of concentrated sulfuric acid is heated to boiling for 2 hours. The acylated monoazo dye obtained after conventional work-up dyes wool from weakly acidic bath in orange-red tones.

Example 5 A mixture of 652 parts of the monoazo dye from diazotized t-aminobenzene-3-sulfonamide and 2-oxynaphthalene, 100 parts trichlorobenzene and 360 parts of benzoyl chloride is heated to 150 to 16o ° for 5 hours with stirring. After cooling and filtering off, 55o parts of the benzoylated monoazo dye are obtained, which dyes wool in orange-red tones.

Example 6 A mixture of 163 parts of the monoazo dye from diazotized i-Aminob @ enzol-4-sulfonami: d and 2-oxynaphthalene, 150 parts of trichlorobenzene: and 84 parts of benzoyl chloride are heated to 130 ° for 3 hours with stirring. After this customary work-up gives 16o parts of the benzoylated monoazo dye, -Dyes the wool in orange-red tones.

Claims (1)

PATENT CLAIM: Process for the production of azo dyes that. containing acylated sulfonamido groups, characterized in that monooxy.azo dyes which contain at least one unsubstituted sulfonamide group are treated with aliphatic or aromatic acylating agents which do not carry any water-solubilizing groups, and the acylated dyes obtained, if desired, in bulk or metal-releasing agents can act on the fiber. Cited publications: French patents nos. 890 049, 913877, 941 336, 488 792, 964 552, 940 852, 914 64o, 914 598, 815 575, 488 792; German Patent No. 82i 977.